US3439817A - Material handling machine - Google Patents

Description

April 22, 1969 T. N. HACKETT MATERIAL HANDLING MACHINE Sheet Filed Sept. 1, 1967 .mulIlHHHHHlH "WI i INVENTOR THEODORE N. HACKETT' ATTORNEYS April 22, 1969 T. N. HACKETT 3,439,317

MATERIAL HANDLING MACHINE Filed Sept. 1, 1967 Sheet 1 of s INVENT OR THEODORE N. HACKETT ATTORNEYS April 22, 1969 "r. N. HACKETT 3,439,817

' MATERIAL HANDLING MACHINE Filed Sept. 1, 1967 Sheet 3 of s as 64 L 50 INVENTOR THEODORE N. HACKETT AITQRNEYS United States Patent 3,439,817 MATERIAL HANDLING MACHINE Theodore N. Hackett, 4324 Rowiand Drive, Salt Lake City, Utah 84117 Filed Sept. 1, 1967, Ser. No. 665,120 Int. Cl. E02f 3/ 62 US. Cl. 214-131 Claims ABSTRACT OF THE DISCLOSURE An overhead rocker bucket type machine includes means at the outer thrust ends of the load supporting rails thereof mounting the rocker arms connected with the bucket for pivotal movement about such ends" of the rail members during initial movement of the bucket u-pwardly during the digging cycle before the curved surfaces of the rocker arms engage the associated rail members to maintain the moment arm from the pivot point to the bucket lift equal throughout the digging portion of he cycle. Means are also provided for limiting downward movement of the bucket.

Background of the invention The present invention relates to a material handling machine, and more particularly, to a machine of the overhead rocker bucket type generally employed for heavy duty underground rock loading, wherein the loader bucket swings through an arc to discharge its load into an associated loading car disposed adjacent to the machine.

In these types of machines, the common prior art arrangements have employed a frame supporting a pair of substantially parallel longitudinally extending rail members having upper surfaces defining load supporting trackways. A shovel bucket is supported by a pair of spaced substantially parallel rocker arms each of which has a curved surface for rolling engagement with one of said trackways during the digging-discharge cycle from a low forward material gathering position adjacent one end of the main frame to an elevated material discharge position adjacent the other end of the main frame.

In conventional arrangement as now employed in the art, when the apparatus is in its low forward material gathering position, the curved surfaces of the rocker arms are in engagement with the supporting trackways of the rail members. Accordingly, upon initial movement of the bucket upwardly at the start of the digging cycle, the rocker arms immediately begin to roll along the supporting trackways of the rail members so that the moment arm from the pivot point defined by the point of engagement of the rocker arm on the rocker arm support rail to the digging lift of the bucket will increase as the bucket is raised and the rocker arms roll along the supporting traclcways, thereby resulting in a decreasing digging force as the bucket moves upwardly through an associated muck pile.

Summary of the invention The apparatus according to the present invention incorporates means supporting the rocker arms thereof for pivotal movement about the outer ends of the associated rail members during initial movement of the bucket upwardly during the digging cycle. This is accomplished by providing arcuate end portions at the outer ends of the two rail members, the rocker arms including cooperating arcuate portions in engagement with the arcuate portions of the rail members so that as the bucket is initially lifted, the rocker arm and bucket assembly is rotating about the center of the arcuate surface at the rail thrust end thereby maintaining the moment arm from this pivot point to the bucket lift constant throughout the digging portion of "ice the rocker arm cycle thereby resulting in the shortest moment arm during digging in the muck pile which gives the highest digging force throughout this critical period of movement.

The curved surfaces of the rocker arms do not come into engagement with the trackway portions of the associated rail members until this initial digging portion of the cycle has taken place, whereupon the load is trans ferred from said arcuate portions to the point of interengagement of the curved surfaces of the rocker arms with the rail members.

The rocker arms and the thrust ends of the rail members have interengaging portions for limiting downward movement of the rocker arms which prevents the bucket from attempting to go down lower than the desired digging position and thereby prevents the machine from tending to jackknife during the digging operation.

Brief description of the drawings FIG. 1 is a side elevation of the material handling machine according to the present invention;

FIG. 2 is a top perspective view illustrating the outer end portions of the two rail members of the apparatus;

FIGS. 3-6, inclusive, illustrate in a somewhat schematic manner of various operative positions of the rocker arm and bucket assembly with respect to the associated supporting rail members at different portions of the digging-discharge cycle.

Description of the preferred embodiment Referring now to the drawings wherein like reference characters designate corresponding parts throughout the several views, as seen in FIG. 1, the material handling machine is indicated generally by reference numeral 10 and it comprises a main frame or body 12 supported by a first pair of wheels 14 at one side thereof, it being understood that a similar pair of wheels are provided at the opposite side of the frame. These wheels are driven by a motor 16 through suitable gearing process (not shown). As illustrated, the wheels are shown as mounted upon rails 18 as are commonly employed in mines, although it should be understood that the frame could as well be mounted on rubber tired wheels or on endless track units and the like if so desired.

The super structure of the machine includes a pair of spaced side frames 20 one of which is visible in FIG. 1, the side frames being disposed at opposite sides of the machine in spaced parallel relationship to one another. An auxiliary cushion pad 22 is mounted upon a suitable cross support member extending between the side frames 20, the purpose of this cushion pad being hereinafter explained.

A first manually operated control mechanism 24 connected with a suitable source of air pressure is adapted to control the forward and rearward movement of the machine along the rails by suitably actuating the motor 16. A second conventional manually operated control mechanism 26 is adapted to control the swinging movement of the upper part of the machine with respect to the lower part thereof in the usual manner, also to control the operation of the means for swinging the rocker arm and bucket assembly through its arc of movement.

The rocker arm and bucket assembly is indicated generally by reference numeral 30 and includes a pair of spaced substantially parallel rocker arms 32 one of which is seen in FIG. 1, each of these rocker arms having supported thereby spring loaded bumper means indicated generally by reference numeral 34. Each of these bumper means is adapted to engage one of said auxiliary cushion pads 22 previously described, a separate cushion pad being disposed at opposite sides at the rear of the machine for engagement with the bumper means 34.

An open side bucket 36 of known design is supported by and extends from the ends of the rocker arms as seen in FIG. 1.

A yoke member 40 extends between the upper ends of the rocker arms as seen in FIG. 1, and a bucket drive chain 42 is secured to this yoke member. The drive chain extends over a steel chain roller 44 supported between the side frames 20, the opposite end of the drive chain being connected with a wheel 42 driven through a suitable gear train and motor arrangement. The reel and drive chain providing means for moving the rocker arms through the digging and discharge cycle in the conventional manner.

Each of the rocker arms is provided with a curved surface 48, and a pair of rail members 50 and 52 as seen most clearly in FIG. 2 which are supported adjacent the inner faces of the side frames 20 are provided with upper surfaces 54 and 56 respectively which define load supporting trackways which are adapted to engage the curved surfaces 48 of the rocker arms. It is apparent that these curved surfaces will have a rolling engagement with the upper surfaces or trackways 54 and 56 as the rocker arms are pivoted during the digging and discharge cycle of the apparatus.

As seen clearly in FIG. 2, the rail member 50 is a unique configuration at the outer thrust end thereof. The upper surfaces 54 of the rail member joins with a downwardly sloping surface 60 which in turn merges with an upwardly sloping surface 62. This surface 62 in turn joins with an arcuate end portion 64 the outer surface of which defines a portion of a cylindrical surface, or in other words, defines a surface having a substantially semi-circular cross section. This end portion 64 in turn joins with a downwardly sloping surface 66. Surface 66 then joins a sharply downwardly sloping surface 68 which intersects the underside 70 of rail member 50. The outer thrust end of rail member 52 is of cylindrical construction, and similar parts have been given the same reference numerals primed.

It should be noted that the arcuate outer end portions 64 and 64' of the two rail members 50 and 52 respectively, are disposed below the upper surfaces 54 and 56 of the associated rail members, and that the centers of curvature 74 and 74' about which these arcuate outer end portions are formed, are disposed substantially below these upper surfaces. These outer end portions are located as low as possible so as to keep the lever arm from this pivot point, which is the center of curvature, to the lift of the bucket as short as possible. This lever arm is indicated by the distance LA as indicated in FIG. 1 of the drawings.

A thrust liner 80 is secured to each of the rocker arms 32. Each of these thrust liners includes an upper end portion 82 and an intermediate pocket portion defining an arcuate surface which is complementary to the arcuate end surfaces 64 and 64 on the rail members. The interengagement between this pocket portion and the outer ends of the rail members enables the rocker arms to pivot about the outer ends of the rail members during initial movement of the bucket upwardly during the digging cycle. Each of the thrust liners also includes a curved guiding surface 86 and a lower end portion 88.

Referring now to FIG, 3 of the drawings, the rocker arm 32 and rail member 50 are illustrated somewhat schematically for the sake of clarity. The thrust liner of the rocker arm is not illustrated as a separate element in this illustration, but the components thereof are indicated by corresponding reference numerals.

In this position of the apparatus, the rocker arm and bucket assembly is in its lower forward material gathering position adjacent one end of the main frame. This represents one limit of movement of the rocker arms, and the rocker arms are moved to the opposite limit of movement in an elevated material discharge position as indicated in phantom line in FIG. 1 wherein the rocker arms are disposed adjacent the opposite end of the main frame. Movement from the position shown in FIG. 3 to the phantom line position shown in FIG. 1 represents a digging-discharge cycle.

As seen in FIG. 3 when the rocker arm and bucket assembly is in its lower forward material gathering position, the lower end 88 of the thrust liner is adapted to engage the underside 70 of rail member 50. The upper end 82 of the thrust liner is adapted to contact the top side of the rail thrust ends in this position, and this cooperating interengagement as described hereinabove prevents the bucket from going down lower than the desired digging position and prevents the machine from tending to jackknife while digging. It will also be noted that in this particular position, the curved surface 48 of the rocker arm is spaced from the upper surface or trackway 54 of the rail member, It will, of course, be understood that the opposite rocker arm is in the same relative position with respect to its associated supporting rail member.

Upon actuation of the reel 46, the rocker arms start to pivot about the arcuate end portions 64 and 64 of the rail members, whereby the arms are actually pivoting about the fixed centers 74 and 74' of the surfaces 64 and 64. This pivotal movement will continue until the apparatus reaches a position as shown in FIG. 4 where a curved surface 48 of the rocker arm 32 initially engages the upper surface 54 of the rail member 50. At this point, the digging portion of the operating cycle in the muck pile is completed, and the rocker arms start to roll back along the rail members along the curved edge 48.

It will be noted that during the digging portion of the operating cycle, the rocker arms pivot about the fixed centers of curvature 74 and 74 of the end portions 64 and 64' of the respective rail members and that the lever arm distance LA as mentioned previously remains constant. Accordingly, the shortest moment arm from the pivot point to the bucket lift is maintained during digging in the muck pile which gives the highest force throughout this period.

Referring now to FIG. 5, upon further pivotal movement of the rocker arm, the thrust liner is completely disengaged from the outer thrust end of the associated rail member and the rocker arms are then completely supported by the upper surfaces of trackways of the associated rail members.

FIG. 6 illustrates a still further position of the rocker arms wherein the rocker arms have pivoted further in a clockwise direction so that the entire rocker arm structure is above the level of the upper surfaces of the associated rail members. It will, of course, be understood that the rocker arms continue to pivot in a clockwise direction until the bumper means thereof engage the cushion pads on the super structure of the machine whereupon the material is forcefully discharged from the open side bucket in the usual manner.

I claim:

1. In a material handling machine of the overhead rocker bucket type, a main frame, a pair of spaced substantially parallel longitudinally extending rail members supported by said main frame, each of said rail members having an upper surface defining a load supporting trackway, a pair of spaced substantially parallel rocker arms each of which has a curved surface for rolling engagement with one of said trackways, a bucket supported by and extending from said arms, said rocker arms being movable from a low forward material gathering position adjacent one end of said main frame to an elevated material discharge position adjacent the opposite end of said main frame to define a digging-discharge cycle, means for moving said rocker arms between said positions, and means supporting said rocker arms for pivotal movement of same about a fixed center of curvature at the outer ends of said rail members during initial movement of the bucket upwardly during the digging cycle.

2. The apparatus as defined in claim 1 wherein the curved surfaces of said rocker arms are spaced from the upper surfaces defined by the associated trackways when said rocker arms are in said low forward material gathering position.

3. The apparatus as defined in claim 2 wherein said curved surfaces are also spaced from the associated upper surfaces of the rail members during initial movement of the bucket upwardly during the digging cycle of the apparatus.

4. The apparatus as defined in claim 1 wherein said means for supporting the rocker arms for pivotal movement about the Outer ends of the rail members comprise arcuate end portions at the outer thrust ends of each of the rails, the curvature of said arcuate end portions being at least substantially 180.

5. The apparatus as defined in claim 4 wherein the arcuate end portions on each of said rail members define portions of a cylindrical surface.

6. The apparatus as defined in claim 4 wherein said arcuate end portions of the rail members are disposed horizontally below the associated upper surfaces of the respective rail members when said upper surfaces are disposed horizontal.

7. The apparatus as defined in claim 1 including interengaging means on said rocker arms and said rail members for limiting downward movement of the rockers arms and bucket supported thereby with respect to said rail members and the main frame.

8. The apparatus as defined in claim 7 wherein said means for limiting downward movement comprises a thrust liner connected with each of said rocker arms, each of said thrust liners having a lower end portion adapted to contact the underside of the associated rail member and also includes an upper end portion adapted to contact the top side of the associated rail member.

9. The apparatus as defined in claim 8 wherein each of said thrust liners includes an arcuate pocket portion adapted to engage an arcuate end portion of an associated rail member, said arcuate portion being complementary to one another to permit pivotal movement of the rockerarms about the rail members.

10. The apparatus as defined in claim 8 wherein each of said thrust liners includes a curved guiding surface adjacent the lower end portion thereof.

References Cited UNITED STATES PATENTS 2,752,053 6/1956 Schwartz et a1 214131 3,111,235 11/1963 Holtermann 2l4768 HUGO O. SCHULZ, Primary Examiner.

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